Prepare 3%-5% acetic acid (the concentration of edible white vinegar is 4%-6%, which can be used as the identification solution for condyloma acuminatum). Apply gauze or paper towel soaked with white vinegar to the growths, and observe whether the protrusions turn white after 3-5 minutes (the wart in the anus needs 10- 15 minutes). If there is obvious whitening of the grower, it can be diagnosed that the treatment drug for condyloma acuminatum is 5-Fu ointment or Youke partner. Because the keratin produced by HPV infected cells is different from that produced by normal uninfected epithelial cells, the former can be decolorized and whitened by acetic acid while the latter does not. The sensitivity of acetic acid white test is very high, which is helpful to diagnose HPV infection, especially subclinical infection. However, false positive reaction can also occur when chronic inflammation caused by other reasons causes epithelial thickening. The margin of false positive reaction whiting area is unclear and irregular.